Coordination of Upper Extremity and Center of Mass Trajectory During Basketball Shots from Varying Distances

Casey Wiens1, Jill L. McNitt-Gray1


1 Department of Biological Sciences, University of Southern California
2 Department of Biomedical Engineering, University of Southern California

Introduction

  • Known
    • Basketball shots are taken from varying distance from hoop
    • Distance affects max angular velocity (Nakano, Fukashiro, and Yoshioka 2018) and timing of max upper extremity joint angular velocities (Podmenik et al. 2017), (Miller and Bartlett 1993) relative to ball release
    • Releasing the ball earlier relative to center of mass (CM) trajectory apex increases the CM vertical velocity contribution to ball vertical velocity (Wiens and McNitt-Gray 2020)
  • Unknown
    • How individuals control their upper extremity in relation to CM trajectory during shooting motion

Hypothesis

  • Upper extremity shot initiation would occur earlier relative to CM trajectory apex

Methods

  • Participants
    • 7 recreational players (4 female; college-aged)
  • Basketball shot at game pace
    • Minimum 10 attempts at each distance
  • Motion capture
    • Ball motion (Panasonic, 120Hz)
  • Force-Time Characteristics
    • Net impulse = change in momentum (Kistler, 1200Hz)
  • Wearable sensors
    • Arm segment motion (APDM, 120Hz)

Stats

  • Upper extremity shot initiation: earliest event of following:
    • Earliest event between: shoulder flexion or elbow extension
  • Within-participant differences between shot distances
    • Multiple comparisons on difference scores
    • p-values adjusted using Benjamini-Hochberg method (Wilcox 2017)

Data

Table 1: Within-participant Comparisons Across Distances
Shot Initiation to Apex (s)
Ball Vv at Release (m/s)
Participant Long Mid Close Long Mid Close
1001 -0.427 -0.366 -0.306 6.245 5.311 4.162
1003 -0.423 -0.355 -0.293 6.817 5.870 4.640
1004 -0.483 -0.384 -0.315 7.004 5.609 4.155
2501 -0.351 -0.309 -0.275 6.703 6.155 5.222
2502 -0.400 -0.351 -0.268 6.255 5.338 4.580
2503 -0.414 -0.402 -0.345 7.420 6.438 5.400
2504 -0.375 -0.326 -0.274 6.705 6.079 5.094
Note:
All comparisons p < 0.001

Results

Discussion

  • Changes in timing of upper extremity shot initiation in relation to CM trajectory apex were associated with differences in ball vertical velocity at release
  • Timing of upper body shooting motion relative to whole body motion may affect ball release angle, subsequently affecting performance outcomes

References

Miller, Stuart, and Roger M. Bartlett. 1993. “The effects of increased shooting distance in the basketball jump shot.” Journal of Sports Sciences 11 (4): 285–93. https://doi.org/10.1080/02640419308729998.

Nakano, Nobuyasu, Senshi Fukashiro, and Shinsuke Yoshioka. 2018. “The effect of increased shooting distance on energy flow in basketball jump shot.” Sports Biomechanics 3141: 1–16. https://doi.org/10.1080/14763141.2018.1480728.

Podmenik, Nadja, Matej Supej, Milan Čoh, and Frane Erčulj. 2017. “The effect of shooting range on the dynamics of limbs angular velocities of the basketball shot.” Kinesiology 49 (1): 92–100. https://doi.org/10.26582/k.49.1.4.

Wiens, Casey, and Jill L. McNitt-Gray. 2020. “The contribution of body center of mass velocity to basketball ball release velocity across shot distances.” In Proceedings of the 38th International Society of Biomechanics in Sports.

Wilcox, Rand. 2017. Modern Statistics for the Social and Behavioral Sciences. Second Edi. Chapman; Hall/CRC. https://doi.org/10.1201/9781315154480.